JP2003039607A - Antistatic hard coat film and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antistatic hard coat film having a large total light transmissivity value, good in the visibility of a display image, excellent in the balance of antistatic properties and scratch resistance and easy to manufacture, and to provide a method for manufacturing the same. SOLUTION: The antistatic hard coat film is constituted by successively providing a hard coat layer (A) comprising an ionizing radiation curable resin, and an antistatic layer (B) with a thickness of 0.03-2 μm comprising the ionizing radiation curable resin containing antistatic particles with a mean particle size of 0.01-2 μm on a substrate film. The Taber abrasion hardness measured according to JIS K5400 of this hard coat film is not more than 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antistatic hard coat film which has both antistatic property and scratch resistance and is used for a display device (display) such as a liquid crystal display device, and a method for producing the same. The present invention relates to an antistatic hard coat film most suitable for an in-line-planing-switching (IPS) liquid crystal display device and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, in a display such as a CRT (CRT) or a liquid crystal display device, as a surface protective material, as shown in FIG.
A hard coat film 80 provided with a hard coat layer 82 having excellent scratch resistance is used. However, in such a hard coat film, since the surface resistance of the hard coat layer itself is usually as large as 1 × 10 ¹³ Ω · cm or more, charged dust and the like existing in the surroundings are
There was a problem that the surface of the hard coat layer was easily electrically attached.

Therefore, in order to reduce the surface resistance of the hard coat layer, as shown in FIG. 6B, a predetermined amount of antimony-doped tin oxide is contained in the hard coat layer 88 provided on the base film 84. Antistatic particles 8 such as (ATO)
There is disclosed an antistatic hard coat film 87 in which 6 is added or an aqueous polymer is added. However, since such an antistatic hard coat film has a relatively thick hard coat layer, in order to obtain a predetermined antistatic effect, a large amount of antistatic particles or an aqueous polymer must be added. In addition, there were problems that the total light transmittance was remarkably lowered and the hard coat property was lowered.

Further, in Japanese Patent Laid-Open No. 11-42729, etc., as shown in FIG. 6C, antistatic particles 86 are contained between the base film 84 and the hard coat layer 82. , An antistatic hard coat film 89 provided with an antistatic layer 88 made of a metal thin film is disclosed. However, since the antistatic layer is located below the relatively thick hard coat layer and is distant from the surface, the surface resistance value is still large and it is difficult to obtain a predetermined antistatic effect. Further, in the disclosed antistatic hard coat film, since the antistatic layer is sandwiched between the electrically insulating hard coat layer and the substrate film, the antistatic layer may be grounded. There was also the problem of difficulty.

Therefore, an antistatic hard coat film has been proposed in which a hard coat layer and an antistatic layer are sequentially laminated on a substrate film so that the antistatic layer is present on the surface. . That is, it has been proposed to irradiate a hard coat film with ionizing radiation to form an antistatic layer made of an ionizing radiation curable resin. However, the thickness of the antistatic layer is usually several microns or less, and even if it is simply irradiated with ionizing radiation, oxygen is inhibited due to the air present in the surroundings, so that curing failure occurs and a predetermined amount is obtained. It was difficult to form an antistatic layer having surface resistance and scratch resistance.

On the other hand, in Japanese Unexamined Patent Publication No. 8-112866, as shown in FIG. 7, after a UV curable resin 92 is applied on a base material 93, an antistatic material is formed on a process paper 94 in advance. Laminate layer 91, then antistatic layer 9
After removing the process paper 94 from the side of 1 or in a state where the process paper is not peeled off, ultraviolet rays 96 are irradiated through the antistatic layer 91 to cure the ultraviolet curable resin 92. A method for producing an antistatic hard coat film is disclosed. However, even if the process paper is used, it is not easy to laminate the antistatic layer and the applied ultraviolet curable resin to a uniform thickness without wrinkles. In particular, when the thickness of the antistatic layer is, for example, a thin film of 5 μm or less, or the width of the antistatic layer is 10 cm or more, the laminating pressure between the antistatic layer and the applied ultraviolet curable resin is increased. There was a problem in that it became non-uniform and lamination was substantially impossible. Further, when the ultraviolet curable resin is photocured, the curing and contraction of the ultraviolet curable resin is greatly performed, so that it becomes more difficult to laminate the antistatic layer and the hard coat layer made of the ultraviolet curable resin. Therefore, even if the antistatic layer and the applied ultraviolet curable resin are aligned with each other before curing, it is not easy to laminate them at a predetermined position after curing. Further, in the disclosed manufacturing method, since the antistatic layer has already been cured and formed, it is difficult to cause a reaction at the interface between the antistatic layer and the hard coat layer. Therefore, the adhesion between the antistatic layer and the hard coat layer is reduced, and the antistatic layer peels off,
There were problems such as not being able to obtain a predetermined scratch resistance. Furthermore, in the disclosed manufacturing method, it is necessary to form the antistatic layer in a separate step, and there are problems such as an increase in the number of manufacturing steps, a long manufacturing time, and a need for process paper. Was given.

[0007]

SUMMARY OF THE INVENTION The inventors of the present invention have
As a result of diligent consideration of the above-mentioned problems, the antistatic layer and the hard coat layer are composed of an ionizing radiation curable resin, and the thickness of the antistatic layer and the average particle diameter of the antistatic particles contained in the antistatic layer, By limiting the Taber abrasion hardness of the hard coat film measured according to JIS K5400 to a value within a predetermined range, while maintaining excellent total light transmittance, a predetermined antistatic property (surface resistivity) can be obtained. ) And scratch resistance were obtained, and the present invention was completed. That is, the object of the present invention is an antistatic hard film that can be easily manufactured and that, when used in a display device, provides excellent total light transmittance, antistatic property, scratch resistance, and the like. To provide a coated film. Another object of the present invention is to provide an antistatic hard coat film having excellent total light transmittance, antistatic property, scratch resistance and the like, which is an efficient method for producing an antistatic hard coat film. To provide.

[0008]

According to the present invention, (A) a hard coat layer made of an ionizing radiation-curable resin and (B) a charge having an average particle size of 0.01 to 2 μm on a base film. An antistatic hard coat film, which sequentially comprises an antistatic layer having a thickness of 0.03 to 2 μm and made of an ionizing radiation-curable resin containing antistatic particles, according to JIS K540.
There is provided an antistatic hard coat film characterized in that the Taber abrasion hardness measured in accordance with 0 is 25 or less, and the above-mentioned problems can be solved. According to this structure, by the function of the antistatic particles contained in the antistatic layer provided on the hard coat layer,
A predetermined antistatic property can be obtained. Moreover, when comprised in this way, when used for a liquid crystal display device etc., the antistatic hard coat film which has the outstanding total light transmittance and abrasion resistance can be easily provided.

In forming the antistatic hard coat film of the present invention, it is preferable that the average particle diameter of the antistatic particles and the thickness of the antistatic layer are substantially equal. According to this structure, in the antistatic layer,
Since the antistatic particles substantially exist as a single layer, light absorption by the antistatic particles can be reduced. Further, with such a configuration, since adjacent antistatic particles are likely to come into contact with each other, it is possible to obtain a predetermined surface resistivity (sometimes referred to simply as surface resistance) with a relatively small amount of addition. Therefore, in the antistatic hard coat film, more excellent total light transmittance and antistatic properties can be obtained.

Further, in forming the antistatic hard coat film of the present invention, the amount of antistatic particles added is
The value is preferably in the range of 50 to 90% by weight with respect to the total amount of the antistatic layer. With this configuration,
In the antistatic layer, a predetermined surface resistivity can be reliably obtained, while the total light transmittance can be controlled to a value equal to or higher than a predetermined value.

In forming the antistatic hard coat film of the present invention, the antistatic layer is preferably patterned. According to this structure, the area of the antistatic layer with respect to the entire area is reduced, so that light absorption by the antistatic layer is reduced and a more excellent total light transmittance can be obtained. Moreover, since a large amount of antistatic particles can be added in proportion to the decrease in the area of the antistatic layer, a predetermined surface resistance value can be reliably obtained. Therefore, in the antistatic hard coat film, more excellent total light transmittance and antistatic properties can be obtained.

In forming the antistatic hard coat film of the present invention, it is preferable that each ionizing radiation curable resin reacts at the interface between the hard coat layer and the antistatic layer. According to this structure, the adhesion between the hard coat layer and the antistatic layer is enhanced, and the mechanical restraint of the antistatic layer by the hard coat layer can be enhanced. Therefore, the mechanical strength and scratch resistance of the antistatic layer can be further improved, and the antistatic layer can be easily thinned.

In forming the antistatic hard coat film of the present invention, it is preferable that the hard coat layer is an antiglare hard coat layer. According to this structure, it is possible to impart antiglare properties to the antistatic hard coat film and effectively eliminate the influence on the external light.

In forming the antistatic hard coat film of the present invention, the antistatic hard coat film used in an in-line-planing-switching (IPS) liquid crystal display device is preferable. With this structure, the structure is weak against static electricity, and 1 ×
I need antistatic property (conductivity) of about 10 ⁸ Ω · cm
Also in the PS liquid crystal display device, it is possible to eliminate the influence of charging due to the antistatic hard coat film. Therefore, when driving the IPS liquid crystal display device, the liquid crystal can be accurately driven by applying a voltage in the horizontal direction.

Another embodiment of the present invention is (A) a first step of irradiating ionizing radiation to form a hard coat layer made of an ionizing radiation-curable resin on a base film.
(B) Irradiating with ionizing radiation, the average particle size is 0.01 to 2
A Taber abrasion hardness of a hard coat film, which is formed by forming an antistatic layer having a thickness of 0.03 to 2 μm, which is made of an ionizing radiation-curable resin containing μm antistatic particles on a hard coat layer and is measured according to JIS K5400. And a second step having a value of 25 or less, and a method for producing an antistatic hard coat film. By carrying out in this manner, it is possible to accurately and easily, on the hard coat layer,
An antistatic layer having a predetermined abrasion resistance can be laminated. Therefore, a predetermined antistatic property can be surely obtained by the action of the antistatic particles contained in the antistatic layer. Further, since ionizing radiation is used, an antistatic hard coat film having excellent total light transmittance and scratch resistance when used in a display device can be provided easily and quickly.

In carrying out the method for producing an antistatic hard coat film of the present invention, in the first step, the hard coat layer is formed in a semi-cured state by irradiation with ionizing radiation, and in the second step. It is preferable to harden the antistatic layer by irradiation with ionizing radiation and further harden the hard coat layer. By carrying out in this way, each ionizing radiation curable resin can be reacted at the interface between the hard coat layer and the antistatic layer. Therefore, the mechanical strength of the antistatic layer can be further improved, and a predetermined scratch resistance can be effectively obtained. Further, by carrying out in this way, even when the reaction inhibition due to the ambient oxygen occurs when the antistatic layer is cured, the initiator remaining in the hard coat layer is effectively utilized to prevent the antistatic The layer can be fully cured.

In carrying out the method for producing an antistatic hard coat film of the present invention, the dose of ionizing radiation in the first step is set to a value of less than 100 mJ / cm ² , and the ionization in the second step is performed. The irradiation dose of radiation is preferably 500 mJ / cm ² or more. By adopting such an irradiation amount, in the first step, there is substantially no surface tack,
It can be easily made into a semi-cured state. Therefore,
Since it is not a liquid resin, an antistatic layer having a uniform thickness can be accurately and easily formed on the hard coat layer. Further, since the hard coat layer is partially cured, even if the curing reaction is promoted by adopting such an irradiation amount in the second step thereafter, the antistatic layer and the hard coat layer are also cured. The layer can be sufficiently cured and the curing shrinkage generated in the hard coat layer can be reduced.

In carrying out the method for producing an antistatic hard coat film of the present invention, at least the second step is carried out.
It is preferable to carry out the step of in nitrogen. By carrying out in this way, it is possible to effectively prevent oxygen inhibition when the antistatic layer is cured by irradiation with ionizing radiation.

Further, in carrying out the method for producing an antistatic hard coat film of the present invention, it is preferable to perform pattern exposure with ionizing radiation in the second step.
By carrying out in this way, it is possible to easily obtain an antistatic layer having a reduced area by patterning. Therefore, it is possible to provide an antistatic hard coat film having further excellent total light transmittance.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION [First Embodiment] In the first embodiment, as shown in FIG. 1A, a hard coat made of (A) an ionizing radiation curable resin is formed on a base film 18. Charging sequentially including a layer 16 and (B) an antistatic layer 14 having a thickness of 0.03 to 2 μm and made of an ionizing radiation curable resin 11 containing the antistatic particles 10 having an average particle diameter of 0.01 to 2 μm. An anti-hard coat film, which is JIS
The Taber abrasion hardness measured according to K5400 is 2
Antistatic hard coat film 20 with a value of 5 or less
Is. Hereinafter, the antistatic hard coat film will be described separately for each constituent element, and will be specifically described with reference to the drawings as appropriate.

1. Base film The type of base film in the antistatic hard coat film is polyethylene terephthalate (PE
T), polycarbonate (PC), polyethylene naphthalate (PEN), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polymethylmethacrylate (PMMA), polysulfone (PS)
U), polyacrylonitrile (PAN), triacetyl cellulose (TAC), and other transparent resin films can be mentioned. Of these substrate films, particularly versatile, because of their excellent transparency and mechanical strength,
It is preferable to use a transparent resin film made of polyethylene terephthalate or polycarbonate.

The thickness of the base film is 6 to 500 μm.
A value within the range of m is preferable. The reason for this is that if the thickness of the base material film is less than 6 μm, the mechanical strength may be significantly reduced, while if the thickness of the base material exceeds 500 μm, the light transmittance is reduced. do it,
This is because the visibility of the displayed image may be insufficient. Therefore, the balance of the mechanical strength and the light transmission becomes better, so that the thickness of the base film is 20 to 2
It is more preferable to set the value within the range of 50 μm.

A primer layer is preferably provided on the surface of the base film. The reason for this is that by providing the primer layer, the adhesion between the base film and the cured product of the ionizing radiation curable resin that constitutes the hard coat layer is improved, and the hard coat layer, and by extension, the antistatic property. This is because the scratch resistance of the layer can be further improved. Here, examples of the constituent material of the primer layer include urethane resin, acrylic resin, epoxy resin, polyester resin, and silicone resin, which may be used alone or in combination of two or more.

The thickness of the primer layer is 1 to 20 μm.
It is preferable that the value is within the range. The reason for this is that the primer effect may not be exhibited when the thickness of the primer layer is less than 1 μm. On the other hand, if the thickness of the primer layer is more than 20 μm, the visibility of the image may be deteriorated when the antistatic hard coat film is formed. Therefore, since the balance between the primer effect and the visibility of the image becomes better,
It is more preferable to set the thickness of the primer layer to a value within the range of 3 to 15 μm.

Further, it is preferable to provide fine irregularities, for example, irregularities of 0.1 to 5 μm on the surface of the base film. That is, in order to improve the adhesiveness between the base film and the hard coat layer and to exert the antiglare effect by the base film, it is preferable to perform a surface treatment for providing fine irregularities. As a method of surface treatment for providing such fine irregularities, for example, a sandblast method or a solvent treatment method for a base film, or a corona discharge treatment, a chromic acid treatment, a flame treatment, a hot air treatment, an ozone / ultraviolet irradiation treatment, etc. And the like.

Further, it is preferable to provide an adhesive layer on the back surface of the base film. The reason for this is that if such an adhesive layer is provided, it can be attached arbitrarily to window glass of buildings and vehicles and other adherends requiring abrasion resistance, abrasion resistance, or antistatic properties. This is because it is possible to wear them. Here, examples of the adhesive include natural rubber, synthetic rubber, acrylic resin, polyvinyl ether resin, urethane resin, and silicone resin. Further, the adhesive may further include a tackifier, a filler, a softener,
Antioxidants, ultraviolet absorbers, cross-linking agents and the like can be added. The thickness of the pressure-sensitive adhesive is usually preferably in the range of 5 to 100 μm, more preferably 10 to 50 μm.

2. Hard Coat Layer (1) Main Agent of Ionizing Radiation Curable Resin The main agent of the ionizing radiation curable resin (may be referred to as a radiation curable transparent resin) constituting the hard coat layer is not particularly limited and is conventionally known. You can choose from those. For example, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) ) Acrylate, neopentyl glycol dihydroxypivalate
(Meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone-modified dicyclopentenyl di
(Meth) acrylate, EO-modified di (meth) acrylate phosphate, allylated cyclohexyl di (meth) acrylate,
Isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, diventaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, pentaerythritol tri
(Meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol penta
(Meth) acrylate, dipentaerythritol hexa
Examples thereof include (meth) acrylates, caprolactone-modified dipentaerythritol hexa (meth) acrylates, urethane acrylates, epoxy acrylates, polyester acrylates, polyol acrylates, and the like, or a combination of two or more thereof.

As the curing agent (including a curing catalyst), for example,
Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenyl Acetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one , 4-
(2-Hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-ta- Shari-butyl anthraquinone, 2-amino anthraquinone, 2-
Methylthioxanthone, 2-ethylthioxanthone, 2
-Chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenonedimethylketal, p-
Examples thereof include dimethylamine benzoate. These may be used alone or in combination of two or more.

In addition, even if the solvent is heated during evaporation,
As a curing agent with less decomposition or deterioration, an oligomer type curing agent having a number average molecular weight of about 500 to 1,000 measured by gel permeation chromatography (GPC) can be preferably used. Specific examples of such an oligomer type curing agent include poly [2-
Hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl]
Propanone], poly [2-hydroxy-2-methyl-1- [4- (1-
Vinyl-phenyl)] propanone], poly [2-hydroxy-2]
-Ethyl-1- [4- (1-methylvinyl) phenyl] propanone], poly [2-hydroxy-2-ethyl-1- [4-vinyl-phenyl] propanone], poly [2-hydroxy-2-methyl] -1- [4- (1
-Methylvinyl) phenyl] butanone], poly [2-hydroxy-2-methyl-1- [4- (1-methyl-phenyl)] butanone], poly [2-hydroxy-2-ethyl-1- [4- (1-methylvinyl) phenyl] butanone], poly [2-hydroxy-2-ethyl-1- [4-vinyl-phenyl] butanone], and the like.

When preparing the hard coat agent,
It is preferable that the addition amount of the curing agent of the component (B) be a value within the range of 0.5 to 30 parts by weight with respect to 100 parts by weight of the main component of the ionizing radiation curable resin of the component (A). The reason for this is
This is because if the amount of the curing agent as the component (B) added is less than 0.5 part by weight, the curing of the ionizing radiation curable resin may be insufficient. On the other hand, if the addition amount of the curing agent as the component (B) exceeds 30 parts by weight, it may be difficult to control the curability of the ionizing radiation-curable resin or the storage stability may decrease. is there. Therefore,
More preferably, the amount of the curing agent as the component (B) added is set to a value within the range of 1 to 20 parts by weight with respect to 100 parts by weight of the main component of the ionizing radiation curable resin as the component (A).

(2) Thickness The thickness of the hard coat layer is preferably set to a value within the range of 2 to 20 μm. The reason for this is that if the thickness of the hard coat layer is less than 2 μm, the Taber abrasion hardness may be extremely high. On the other hand, if the thickness of the hard coat layer exceeds 20 μm, the curl may increase. Therefore, it is more preferable to set the thickness of the hard coat layer to a value within the range of 5 to 15 μm in consideration of the Taber abrasion hardness and the occurrence of curl.

(3) Filler Further, in order to improve antiglare property and scratch resistance, the ionizing radiation curable resin constituting the hard coat layer contains various fillers to form a hard coat layer containing a filler. It is preferable. For example, as a preferable filler,
Examples thereof include silica particles, polyester particles, polystyrene particles, acrylic resin particles, and the like, or a combination of two or more kinds.

3. Antistatic Layer (1) Ionizing Radiation Curable Resin As the ionizing radiation curable resin used to form the antistatic layer, it is preferable to use the same ionizing radiation curable resin as that used for the hard coat layer. . The reason for this is that when configured in this manner, the adhesion between the antistatic layer and the hard coat layer is improved, and as a result, excellent anti-scratch resistance can also be obtained in the antistatic layer. .

(2) Types of Antistatic Particles As the types of antistatic particles (conductive particles), tin-doped indium oxide, antimony-doped tin oxide, tin oxide, zinc antimonate, antimony pentoxide, etc. may be used alone or. A combination of two or more kinds can be mentioned. Of these, tin oxide and tin-doped indium oxide are more preferably used because they can be more uniformly mixed and dispersed in the ionizing radiation curable resin.

Average particle size Further, it is preferable that the average particle size of the antistatic particles is set to a value within the range of 0.01 to 2 μm. The reason for this is that when the average particle diameter of such antistatic particles is less than 0.01 μm, a large number of particles are overlapped with each other, and the value of total light transmittance may be significantly reduced. This is because the electrical resistance between particles becomes high, and as a result, the surface resistivity value may become large. On the other hand, when the average particle diameter of the antistatic particles exceeds 2 μm, sedimentation or the like is likely to occur, which makes the handling difficult, or
This is because the surface smoothness may decrease. Therefore, it is more preferable to set the average particle size of the antistatic particles to a value within the range of 0.05 to 1 μm, because the total light transmittance and the handling property of the antistatic particles are better balanced. It is more preferable to set the value within the range of 0.1 to 0.5 μm.

Addition Amount The addition amount of antistatic particles is preferably set to a value within the range of 50 to 90% by weight based on the total amount of the antistatic layer. The reason is that the addition amount of such antistatic particles is 5
This is because when the value is less than 0% by weight, the electric resistance between adjacent antistatic particles becomes high, and as a result, the surface resistivity value may become large. On the other hand, if the addition amount of the antistatic particles exceeds 90% by weight, a large number of particles are overlapped with each other and the value of total light transmittance may be significantly reduced. Therefore, since the balance between the surface resistivity and the total light transmittance is better, the addition amount of the antistatic particles is 55-55 with respect to the total amount of the antistatic layer.
More preferably, the value is within the range of 85% by weight, and 6
It is more preferable to set the value within the range of 0 to 80% by weight.

Powder resistance Further, the powder resistance (volume resistance) of the antistatic particles is set to 100
The value is preferably 0 Ω · cm or less. The reason is that the powder resistance of the antistatic particles is 1,000 Ω · c.
When the value exceeds m, the electric resistance between the adjacent antistatic particles becomes high, and as a result, the value of the surface resistivity becomes large, or in order to obtain a predetermined surface resistivity,
This is because a large amount must be added, and the total light transmittance may decrease.

(3) Thickness In the present invention, the thickness of the antistatic layer is 0.03 to.
It is characterized in that the value is within a range of 2 μm. The reason for this is that when the thickness of the antistatic layer is less than 0.03 μm, the Taber abrasion hardness becomes extremely high,
This is because the surface resistivity value becomes high. Further, when the thickness of the antistatic layer is a value less than 0.03 μm, the haze value may be increased in some cases. on the other hand,
This is because when the thickness of the antistatic layer exceeds 2 μm, sedimentation of the antistatic particles is likely to occur and the surface smoothness may deteriorate. Therefore, it is more preferable to set the thickness of the antistatic layer to a value within the range of 0.03 to 1 μm in consideration of the values of Taber abrasion hardness and surface resistivity.

Here, referring to FIGS. 1A to 1C,
The relationship between the thickness of the antistatic layer 14 and the antistatic particles 10 and the ionizing radiation curable resin 11 in the antistatic layer 14 will be described. In FIG. 1A, the thickness of the antistatic layer 14 and the average particle diameter of the antistatic particles 10 are substantially equal, and the thickness of the ionizing radiation curable resin 11 is also the same. It is a value almost equal to the average particle diameter of. Therefore, the antistatic particles are arranged substantially in a single layer, and the adjacent antistatic particles are in electrical contact with each other in the lateral direction, but the overlapping in the vertical direction is small. That is, light absorption in the antistatic layer is reduced, the total light transmittance is increased, and the surface resistivity is decreased. Further, while an appropriate amount of ionizing radiation curable resin is present around the particles of the antistatic particles, it can also sufficiently adhere to the lower hard coat layer, so that excellent scratch resistance can be obtained and the Taber can be obtained. The value of wear hardness is significantly reduced. Further, FIG. 1B assumes that the thickness of the antistatic layer 14 is relatively thin, and the thickness of the ionizing radiation curable resin 11 is larger than the average particle diameter of the antistatic particles 10. For small cases. Therefore, also in this case, the antistatic particles are arranged substantially in a single layer, and adjacent antistatic particles are in electrical contact with each other in the lateral direction, so that for the surface resistivity and the total light transmittance, Allowable values are obtained. Furthermore, FIG. 1C assumes that the thickness of the antistatic layer 14 is relatively large, and the thickness of the ionizing radiation curable resin 11 is larger than the average particle diameter of the antistatic particles 10. Is also large. Therefore, the antistatic particles may overlap in the vertical direction, and the total light transmittance,
The surface resistivity is slightly reduced. On the other hand, since the amount of the ionizing radiation curable resin existing around the antistatic particles is large, it is easy to firmly fix the antistatic particles or sufficiently adhere to the lower hard coat layer, which is excellent. While abrasion resistance is obtained, the Taber abrasion hardness value can be significantly reduced.

(4) Arrangement It is also preferable to stack and dispose the antistatic layer in the vertical direction with the hard coat layer sandwiched therebetween. With such a structure, and by electrically connecting the antistatic layer existing in the vertical direction by the electric connection member (including ground), a further excellent antistatic effect can be obtained. The structure of the antistatic layer disposed below may be the same as the structure of the antistatic layer disposed above as described above, or may be different from that of the antistatic layer disposed above. It is also possible.

(5) Pattern Also, as shown in FIGS. 2A to 2C, the antistatic layer 1
4 is preferably patterned. Here, FIG.
(A) is an example in which the antistatic layer 14 is linearly patterned on the hard coat layer 16. In addition, FIG. 2 (B)
Is an example in which the antistatic layer 14 is patterned in a line shape, and a part or all of the hard coat layer 16 is embedded to smooth the surface. And FIG. 2 (B)
Then, the common electrode 30 for conducting each line is provided at the end of the line-shaped antistatic layer 14, and the antistatic layer 1
4 is an example in which the surface resistivity of No. 4 is lowered. Also, FIG.
(C) is an example in which another line-shaped antistatic layer 31 is provided so as to be orthogonal to the line-shaped antistatic layer 14 to form a grid pattern as a whole. By patterning the antistatic layer 14 in this way, the area of the antistatic layer can be reduced while maintaining an excellent surface resistance value. Therefore, as the area of the antistatic layer is reduced, the value of total light transmittance can be significantly increased.

Here, specifically, another example of the plane pattern of the antistatic layer is shown in FIGS. Figure 3
As shown in (A) and (B), by using a horizontal line-shaped pattern or a vertical line-shaped pattern, the area of the antistatic layer can be quantitatively maintained while maintaining a predetermined antistatic effect. Can be lowered. Further, by patterning in this way, it is easy to match the direction of the scanning line of the liquid crystal display device or the like, and thus the display image can be recognized more clearly. Further, as shown in FIG. 3C, the lattice-shaped (diamond-shaped) pattern has an advantage that it is easy to ground at the end. Furthermore, as shown in FIG. 3D, a combination of a concentric circular pattern and a horizontal line pattern allows a display screen of a liquid crystal display device or the like to be viewed with a predetermined viewing angle. Even if there is, the displayed image can be recognized more clearly.

(6) Surface resistivity Further, the surface resistivity (surface resistance) of the antistatic layer is 1 × 10.
It is preferable to set the value within the range of ⁴ to 1 × 10 ¹⁰ Ω · cm. This is because the antistatic layer has a surface resistivity of 1
In order to obtain a value of less than × 10 ⁴ Ω · cm, the amount of antistatic particles to be added must be increased, and many antistatic particles are overlapped with each other, resulting in a marked decrease in the total light transmittance. This is because there are cases. On the other hand, when the surface resistivity of the antistatic layer is higher than 1 × 10 ¹⁰ Ω · cm, the antistatic effect is lowered, and it is possible to effectively prevent dust and the like from adhering to the screen of a normal liquid crystal display device. This is because it may be difficult. Therefore, since the balance between the total light transmittance and the antistatic effect is better, the surface resistivity of the antistatic layer should be a value within the range of 5 × 10 ^{4 to} 5 × 10 ⁹ Ω · cm. Is more preferable.

On the other hand, when the liquid crystal display device employs the IPS liquid crystal driving method, the surface resistivity of the antistatic layer is 1
It is preferable to set the value within the range of × 10 ^{4 to} 5 × 10 ⁸ Ω · cm. The reason for this is that if the surface resistivity of the antistatic layer is higher than 5 × 10 ⁸ Ω · cm, the liquid crystal drive in the planar direction may be hindered. Therefore, when the liquid crystal display device adopts the IPS liquid crystal driving method, the surface resistivity of the antistatic layer is 5 × 10 ^{4 to} 3 ×.
A value within the range of 10 ⁸ Ω · cm is more preferable, and a value within the range of 1 × 10 ⁵ to 1 × 10 ⁸ Ω · cm is further preferable.

4. Characteristics of Hard Coat Film (1) Taber Abrasion Hardness In the present invention, the Taber abrasion hardness of the antistatic hard coat film measured according to JIS K5400 is set to a value of 25 or less. The reason for this is that if the Taber abrasion hardness exceeds 25, the scratch resistance may be significantly reduced. Therefore, since the abrasion resistance and the antistatic property are further improved, the Taber abrasion hardness of the antistatic hard coat film is 2
A value of 2 or less is more preferable. The Taber abrasion hardness of the antistatic hard coat film can also be measured by the method described in Example 1 described later.

(2) Total light transmittance Further, it is preferable to set the total light transmittance of the antistatic hard coat film to a value within the range of 80 to 99%. The reason is that when the total light transmittance is less than 80%,
This is because the visibility of the antistatic hard coat film may decrease. On the other hand, the total light transmittance is 99
This is because if it exceeds%, the antistatic property and the scratch resistance may relatively decrease. Therefore, since the balance between the visibility and the antistatic property of the antistatic hard coat film becomes better, the total light transmittance of the antistatic hard coat film is set to a value within the range of 83 to 98%. Is more preferable. The total light transmittance of the antistatic hard coat film can be measured by the method described in Example 1 described later.

(3) Haze value The haze value of the antistatic hard coat film is 0.1 to 0.1%.
A value within the range of 5% is preferable. The reason for this is
This is because if the haze value is less than 0.1%, the amount of antistatic particles added may be excessively limited, and the antistatic properties may be insufficient. On the other hand, when the haze value exceeds 5%, the light transmittance may be relatively reduced and the visibility may be reduced. Therefore, the balance between the antistatic property and the light transmittance becomes better,
It is more preferable to set such a haze value within a range of 0.1 to 4%. The haze value can be measured by the method described in Example 1 described later.

[Second Embodiment] A second embodiment is a method for producing an antistatic hard coat film, which comprises the following first step and second step. First step: a step of irradiating ionizing radiation to form a hard coat layer made of an ionizing radiation curable resin on a base film. Second step: (B) irradiating with ionizing radiation to hard coat an antistatic layer having a thickness of 0.03 to 2 μm made of an ionizing radiation curable resin containing antistatic particles having an average particle size of 0.01 to 2 μm. Formed on a layer and JIS K540
This is a second step in which the Taber abrasion hardness of the hard coat film measured in accordance with 0 is set to a value of 25 or less.

1. First Step (1) Preparation Step of Hard Coat Agent This is a step of uniformly mixing the compounding materials to prepare a hard coat agent for forming a hard coat layer. The hard coat agent is prepared by using (A) an ionizing radiation-curable resin main agent as described below, (B) an ionizing radiation-curable resin curing agent (including a curing catalyst), and (C) a solvent. Is preferably mixed uniformly.

Component (A) The same content as that of the ionizing radiation curable resin (transparent resin) of the component (A) described in the first embodiment can be used.

Component (B) The content can be the same as that of the curing agent of component (B) described in the first embodiment.

Component (C) Examples of the solvent for the component (C) include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, pentyl alcohol, ethyl cellosolve, benzene, toluene, Xylene, ethylbenzene,
Cyclohexane, ethylcyclohexane, ethyl acetate,
Examples thereof include butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, water and the like. Two or more kinds of the above solvents may be combined. In particular, methyl alcohol, because it can easily dissolve ionizing radiation curable resins such as acrylic monomers,
It is preferable to use alcohols such as ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol and pentyl alcohol.

In addition to the hard coat agent, known additives such as a defoaming agent and a leveling agent may be added, if desired.

(2) Application Step of Hard Coating Agent Next, as shown in FIGS. 4 (A) and 4 (B), a base film 18 is prepared, and the hard coating agent prepared in (1) is applied thereon. 50 is applied so that the film thickness after curing is in the range of 2 to 20 μm, preferably 5 to 15 μm.
The value should be within the range. Further, the thickness of the coating layer can be controlled by calculating the required coating amount of the hard coating agent from the solid content concentration of the hard coating agent and the density of the hard coating layer after curing. The method for applying the hard coat agent is not particularly limited, and known methods such as bar coating method, knife coating method, roll coating method, blade coating method and die coating method can be used.

(3) Curing Step Next, as shown in FIG. 4 (C), in the present invention,
The coating (ionizing radiation curable resin) 50 of the hard coat agent obtained by evaporating the solvent through the heating step is irradiated with ionizing radiation R, for example, ultraviolet ray or electron beam to be cured,
It is preferable to form the hard coat layer 16 in a semi-cured state. That is, when it is carried out in this manner, each of the ionizing radiation curable resins can react at the interface between the hard coat layer and the antistatic layer when the antistatic layer is cured and formed. Therefore, the mechanical strength of the antistatic layer can be further improved, and a predetermined scratch resistance can be effectively obtained. Further, by carrying out in this way, even when the reaction inhibition due to the ambient oxygen occurs when the antistatic layer is cured, the initiator remaining in the hard coat layer is effectively utilized to prevent the antistatic This is because the layer can be sufficiently cured.

In forming the semi-cured hard coat layer, for example, when ultraviolet rays are radiated, it is preferable that the amount of irradiation of the ionizing radiation-curable resin is less than 100 mJ / cm ² . The reason for this is that when the ultraviolet irradiation dose reaches a value of 100 mJ / cm ² or more, the hard coat layer is excessively hardened, so that the ionizing radiation curable resin is hardened at the interface between the hard coat layer and the antistatic layer. This is because it may be difficult to react. However, if the hard coat layer is not cured at all, it becomes difficult to laminate the ionizing radiation curable resin for forming the antistatic layer to a uniform thickness, or the hard coat layer is cured in the next step. This is because the contraction may become excessively large. Therefore, when forming a hard coat layer in a semi-cured state, the amount of UV irradiation should be 5
The value within the range of 0 to 90 mJ / cm ² is more preferable, and the value within the range of 60 to 80 mJ / cm ² is further preferable. There is no particular limitation on the type of radiation irradiation device (ultraviolet irradiation device) used for forming the semi-cured hard coat layer. For example, a high pressure mercury lamp, a xenon lamp, a metal halide lamp, a fusion H lamp, etc. are used. The ultraviolet irradiator and the electron beam irradiator that have been used can be used.

2. Second Step (1) Preparation Step of Antistatic Agent Such an antistatic agent is prepared by (a) a main agent of an ionizing radiation curable resin (transparent curable resin) and (b) a curing agent of an ionizing radiation curable resin. It is preferable to carry out by uniformly mixing (including a curing catalyst), (c) a solvent, and (d) antistatic particles.

(2) Step of Applying Antistatic Agent Next, as shown in FIG. 4D, the adjusted antistatic agent 52 is applied onto the hard coat layer 16 in a semi-cured state. Similar to the step, it is preferable to apply by using, for example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method or the like.

(3) Curing Step 1 Next, as shown in FIG. 4 (E), ionizing radiation R is irradiated to cure the hard coat layer 16 in a semi-cured state and simultaneously cure the antistatic layer 14. It is preferable to form it. That is, the irradiation amount of ultraviolet rays when the antistatic layer is formed together with the semi-cured hard coat layer has a strong influence on the Taber abrasion hardness and surface resistance of the antistatic hard coat film. Therefore, in order to obtain excellent Taber abrasion hardness, for example, Taber abrasion hardness of 25 or less, it is effective to set the ultraviolet ray irradiation amount to a value of 500 mJ / cm ² or more.

(4) Curing Step 2 In curing the ionizing radiation curable resin, as shown in FIG.
As shown in (A), a semi-cured hard coat layer 16;
After preparing the antistatic layer 52 before curing, it is preferable to irradiate the ionizing radiation R through the photomask 55 as shown in FIG. When carried out in this way, FIG.
This is because, as shown in (C), formation of the patterned antistatic layer 56 becomes extremely easy. However, if only the ionizing radiation R is radiated via the photomask 55,
The semi-cured hard coat layer 16 may be insufficiently cured. Therefore, although not shown, it is more preferable to irradiate the ionizing radiation R again after the state shown in FIG.

[0061]

EXAMPLES The present invention will be described in more detail below with reference to examples assuming antistatic hard coat films. However, needless to say, the examples show one aspect of the present invention, and the scope of the present invention is not limited to the description of the examples.

[Example 1] 1. Preparation of antistatic hard coat film (1) Preparation of coating liquid for hard coat In a container equipped with a stirrer, the compounding materials of the coating liquid for hard coat were stored in the following proportions, and then uniformly mixed using a stirrer, A coating liquid for hard coat having a solid content concentration of 50% was prepared. UV-curable acrylic hard coating agent containing curing agent Seika Beam EXF-01L (NS) (manufactured by Dainichiseika Kogyo Co., Ltd.) (solid content concentration 100%) 100 parts by weight Isobutyl alcohol 100 parts by weight

(2) Formation of Semi-Hardened Hard Coat Layer The coating solution for hard coat thus obtained was applied to a substrate having a thickness of 50.
It was coated on a polyethylene terephthalate film having a thickness of 5 μm using a bar coater so that the thickness after curing was 5 μm. After that, the coated article made of the coating solution for hard coat was dried in an oven at 80 ° C. for 1 minute.
Then, using a UV irradiator UB042-5AM / w (manufactured by Eye Graphic Co., Ltd.), an ultraviolet ray is applied to the coating material made of the coating liquid for hard coat so that the irradiation amount is 80 mJ / cm ² . The hard coat layer was in a semi-cured state.

(3) Formation of Antistatic Layer After containing the compounding materials of the coating liquid for antistatic layer in the following ratio in a container equipped with a stirrer, they were uniformly mixed using a stirrer to obtain a solid content concentration of 3%. A coating liquid for antistatic layer was prepared. UV-curable acrylic hard coating agent containing curing agent Seika Beam EXF-01L (NS) (manufactured by Dainichi Seika Kogyo Co., Ltd.) (solid content concentration 100%) 100 parts by weight Particle diameter 0.1 μm Isobutyl alcohol of antimony-doped tin oxide Dispersion solution SN-100P (manufactured by Ishihara Techno Co., Ltd.) (concentration of solid content: 30%) 1000 parts by weight Isobutyl alcohol 12233 parts by weight

Next, the coating liquid for antistatic layer was applied using a bar coater, and the obtained coating product was dried in an oven at 80 ° C. for 1 minute. Then, by using an ultraviolet irradiation device, ultraviolet rays are irradiated so that the irradiation amount is 700 mJ / cm ² , and the hard coat layer in a semi-cured state is cured, and the coating material for the antistatic layer is cured. Formed. In this way, an antistatic hard coat film was produced, and the thickness of the hard coat layer was 5
μm, and the thickness of the antistatic layer was 0.1 μm.

2. Evaluation of antistatic hard coat film (1) Scratch resistance (Taber abrasion hardness)
The Taber abrasion hardness was measured according to K5400. That is, a wear resistance test was performed under the following conditions, and the difference in haze value (measured in accordance with JIS K6714) before and after the wear resistance test was measured to obtain Taber wear hardness. Wear wheel: CS-10F Load: 250g Rotation speed: 100 times

(2) Surface Resistivity The surface resistivity of the obtained antistatic hard coat film was measured using a parallel electrode connected to a digital electrometer manufactured by Advantest Corporation.

(3) Total Light Transmittance The total light transmittance of the obtained antistatic hard coat film was measured by a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd.) according to JIS K6714.

(4) Initial haze value The haze value of the obtained antistatic hard coat film was measured according to JIS K6714, and the initial haze value was measured by a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd.).

(5) Steel wool hardness The surface of the obtained antistatic hard coat film is # 0.
After rubbing with 000 steel wool, the appearance was observed and the steel wool hardness was evaluated according to the following criteria. ◯: No noticeable change in appearance was observed. X: Occurrence of scratches or change in color tone was observed.

[Examples 2 to 4 and Comparative Examples 1 and 2] Table 1
An antistatic hard coat film was prepared and evaluated in the same manner as in Example 1 except that the thickness of the antistatic layer and the ultraviolet irradiation amount in the first step were changed as shown in FIG. The results obtained are shown in Table 1.

[0072]

[Table 1]

[0073]

EFFECT OF THE INVENTION According to the antistatic hard coat film of the present invention, not only excellent antistatic property but also excellent visibility and scratch resistance can be obtained. Therefore, such an antistatic hard coat film can be expected to be used, for example, as a hard coat film for liquid crystal display devices and IPS liquid crystal display devices, or as a protective film for various displays.

Further, according to the method for producing an antistatic hard coat film of the present invention, an antistatic hard coat film is obtained which is excellent in antistatic property and is also excellent in visibility and scratch resistance. , Can be manufactured efficiently.

[0075]

[Brief description of drawings]

FIG. 1 is a sectional view of an antistatic hard coat film or the like of the present invention.

FIG. 2 is a perspective sectional view of an antistatic hard coat film of the present invention.

FIG. 3 is a plan view of a patterned antistatic layer.

FIG. 4 is a diagram showing a production example of the antistatic hard coat film of the present invention.

FIG. 5 is a diagram showing a production example of an antistatic hard coat film having a patterned antistatic layer of the present invention.

FIG. 6 is a view provided for explaining a conventional antistatic hard coat film.

FIG. 7 is a diagram provided for explaining a conventional method for producing an antistatic hard coat film.

[0076]

[Explanation of symbols]

10 Antistatic Particles 11 Ionizing Radiation Curable Resin 14 Antistatic Layer 16 Hard Coat Layer 18 Base Film 20, 22, 24, 25, 26, 27 Antistatic Hard Coat Film 30 Common Electrode 31 Antistatic Layer 55 Photomask

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F006 AA12 AA31 AA35 AA36 AB24                       BA02 BA07 CA05 DA04 EA03                 4F100 AA28 AK01B AK01C AK25                       AK42 AT00A BA03 BA07                       BA10A BA10C CA22C DE01C                       EH46 EJ08 EJ42 EJ54 GB41                       JB14B JB14C JG03 JG03C                       JK12B JN01 YY00C

Claims (12)

[Claims] 1. A hard coat layer comprising (A) an ionizing radiation curable resin and (B) an ionizing radiation curable resin containing antistatic particles having an average particle size of 0.01 to 2 μm on a substrate film. An antistatic hard coat film sequentially including an antistatic layer having a thickness of 0.03 to 2 μm, and having a Taber abrasion hardness of 25 or less measured according to JIS K5400. Antistatic hard coat film to be. 2. The antistatic hard coat film according to claim 1, wherein the average particle diameter of the antistatic particles and the thickness of the antistatic layer are substantially equal to each other. 3. The charging according to claim 1, wherein the addition amount of the antistatic particles is set to a value within a range of 50 to 90% by weight with respect to the total amount of the antistatic layer. Preventive hard coat film. 4. The antistatic hard coat film according to claim 1, wherein the antistatic layer is patterned. 5. The charging according to any one of claims 1 to 4, wherein each of the ionizing radiation curable resins reacts at the interface between the hard coat layer and the antistatic layer. Preventive hard coat film. 6. The antistatic hard coat film according to any one of claims 1 to 5, wherein the hard coat layer is an antiglare hard coat layer. 7. The antistatic hard coat film according to claim 1, which is used on the surface of an IPS liquid crystal display device. 8. A first step of (A) irradiating with ionizing radiation to form a hard coat layer made of an ionizing radiation-curable resin on a substrate film, and (B) irradiating with ionizing radiation to obtain an average particle diameter. Is formed on the hard coat layer with a thickness of 0.03 to 2 μm, which is made of an ionizing radiation curable resin containing antistatic particles of 0.01 to 2 μm, according to JIS K540.
And a second step of setting the Taber abrasion hardness of the hard coat film measured according to 0 to a value of 25 or less, a method for producing an antistatic hard coat film. 9. The hard coat layer is formed in a semi-cured state by irradiation with ionizing radiation in the first step, and is formed by curing the antistatic layer by irradiation with ionizing radiation in the second step. Along with this, the hard coat layer is further cured, and the method for producing an antistatic hard coat film according to claim 8. 10. The dose of ionizing radiation in the first step is set to a value of less than 100 mJ / cm ² , and
The dose of ionizing radiation in the second step is 500 m
The method for producing an antistatic hard coat film according to claim 8 or 9, wherein the value is J / cm ² or more. 11. The method for producing an antistatic hard coat film according to claim 8, wherein the second step is performed in nitrogen. 12. The patterning exposure of the ionizing radiation in the second step.
2. The method for producing an antistatic hard coat film according to any one of 1.